The Survey Research Center at the Institute for Social Research at the University of Michigan will continue data collection activities for this longitudinal study and produce datasets in co{lat}oration with the University of Southern California for public release. The purpose of this study is to continue longitudinal data collection activities to assess a variety of cognitive abilities using different modes of administration. In particular, we will conduct follow-up interviews with participants in two samples - Cognition and Aging in the USA (CogUSA) and the National Growth and Change Studies (CogNGCS). For this project, we propose to conduct measurements of the CogUSA participants on up to four separate occasions and CogNGCS participants on two occasions using both telephone and internet modes of administration (i.e., a total of >6,800 tests during this project period). Telephone and internet survey instruments will be developed in coliaboration with John J. McArdle at the University of Southern California. In addition, we will collect saliva samples from these participants for genetic material analysis. Data will be analyzed to examine data quality prior to delivering the data to the University of Southem California research team. These data will be used to create a large, longitudinal public-use dataset that will be analyzed and used to understand age trends in cognitive abilities, the measurement of different cognitive abilities in multiple modes of administration, the relationship of cognitive abilities and trajectories to genetic characteristics, and relations to economic behavior indicators, based on a continued collaboration with the Cognitive Economics (CogEcon) project team directed by Robert J. Willis, In addition, these data may be used to inform HRS Co-Investigators about how to improve upon existing HRS cognitive measures in future waves of the HRS, particularly in relation to the validity of cognitive testing via the telephone and internet.